Piston ring splitting and trimming machine



July 17, 1951 A. H. BATES 2,560,549

PISTON RING SPLITTING AND TRIMMING MACHINE Filed Jan. 1, 1945 l 2 Sheets-Sheet l July 17, 1951 A. H. BATES 2,

PISTON RING SPLITTING AND TRIMMING MACHINE Filed Jan. 1, 1945 2 Sheets-Sheet 2 Patented July 17, 1951 PISTON RING SPLITTING AND TRIMMING MACHINE Albert H. Bates, Rockford, lll., assignor to Burd Piston Ring Company, Rockford, Ill., a corporation of Illinois Application January 1, 1945, Serial No. 570,999

6 Claims. 1

This invention relates to an improved machine for cutting the gaps in piston rings and thereafter trimming the gaps to a predetermined width in relation to outside diameter.

The principal object of my invention is to provide in a single compact machine facilities for lining up in a series of rings the notches that are cast in the inner peripheries at the gap points and other facilities for supporting a stack of rings thus aligned and moving the same at a feed rate toward the gap cutters and gap miller, which are arranged on opposite sides of a sizing ring through which the rings, after the gaps are cut therein, are caused to move for compression down to a predetermined outside diameter, preparatory to the milling operation. This combining of operations in such a practical and eflicient manner obviously means a considerable saving in time and labor and a corresponding reduction in the cost of production of piston rings, besides insuring closer uniformity in the product.

Another object is to provide a machine of the kind mentioned, in which the same rod that is used for lining up the notches in the rings is adapted to be used in transferring the stack of aligned rings onto the V-bed of the machine, means being provided in the machine for support of said rod at its opposite ends to insure keeping the notches aligned up to the time the gap is cut, the rings sliding on the rod as a guide until they reach the gap cutters, and other provision being made for thereafter guiding the rings by their gaps up to the point where the rings have their gaps milled to size inrelation to their outside diameter.

The invention-is illustrated in the accompanying drawings, in which- Fig. 1 is a view partly in side elevation and partly in longitudinal section of a machine made in accordance with my invention;

Fig. 2 is a cross section on the line 2-2 of Fig. 1, and

Figs. 3 and 4 show the closed ring blank and the same ring after the splitting and trimming operation, respectively.

The same reference numerals are applied to corresponding parts throughout the views.

Piston rings for automotive engines are cast out of round; the ring is then side ground to produce true, fiat, smooth and parallel surfaces on both sides. An elliptical ring blank of this kind is illustrated at It in Fig. 3 and has a notch I I cast in its inner periphery in that portion l2 between the parallel dotted lines l3 and M, which is ultimately cut out to form a gap and leave the ring in the form of an open, resilient spring like that illustrated at '15 in Fig. 4. The gap ,l6 in the ring I5 is wide enough so that the ring is compressible to circular form. The gap indicated at 18 is a trifle wider than the gap Iii-l4 produced by cutting out the slug I2 from the blank I0, because, as will soon appear, the ring l5, after the so-called splitting operation, is milled in the gap in a so-called trimming operation to make the gap a predetermined width in relation to the outside diameter of the ring. The rings, after the split and trim operations, are machined on their outer and inner peripheries and may, if necessary, be given a finish trim operation in the gap. However, the machine of the present invention is concerned only with the splitting and trimming operations. I

The machine comprises a base ll, on one endof which is mounted a hydraulic cylinder l8 containing the ram l9 used for moving a stack of rings like those indicated in dotted lines at 20 at a feed rate toward the other end of the base toward the gap cutters 2|, sizing ring 22 and gap miller 23. The sizing ring 22 is formed as part of a standard 24 that is suitably detchably secured onto the end portion of the base. A horizontal V-pbed 25 extends longitudinally of the base between the cylinder I8 and standard 24, and the ram [9 is movable lengthwise thereof between the laterally and vertically adjustable side pieces 26 forming said V-bed. The side pieces 26 are adjusted to support the stack 20 in coaxial relationship to the sizing ring 22 so that the rings will enter the large inner end of the tapered portion 21 of the bore of said ring as the stack is moved by the ram toward the ring along said bed. The rings in the stack 20 are closed blanks like that shown in Fig. 3 from the face plate 28 on the ram l9 up to the gap cutters 2|, but the cutters 2| cut out of the lugs l2, and hence those rings from the cutters 2| forwardly are all split rings similar to that shown in Fig. 4 and are therefore compressible radially to substantially circular form. These split rings, in moving forwardly through the tapered potion 21 of the bore of the sizing ring 22 at a feed rate in the movement of the stack 20, are gradually compressed radially, as illustrated in dotted lines at 29 in Fig. 1, until they reach the short end portion ll of the bore of the sizing ring that is of a. uniform; predetermined diameter. The diameter of the end portion 30 of the bore is only a few thousandths of an inch larger than the predetermined outside diameter of the rings in relation to which the gaps 16 are to be milled to a predetermined 3 width, and the gap milling cutter 23 is of a thickness that will insure milling of the gaps l6 to said predetermined width.

A cylindrical rod 3| that is substantially horizontally disposed, parallel to and above th longitudinal center line of the V-bed 25, has one end fitting slidably in a hole 32 provided therefor in the face plate 28 on the ram l9, and has its other end supported in a longitudinally extending groove 33 provided in a bracket 34 suitably secured at 35 to the inner side of the sizing ring 22. The rod 3| fits in the aligned notches II in the cast ring blanks l0, forming the large rear portion of the stack 20, and acts as a guide for the ring blanks in the movement of the stack toward the cutters 2| to keep the notches II in alignment and insure the cutting out of the slugs l2 from the'proper portion of the ring blanks, the

. blanks being of elliptical form, as disclosed in Fig. 3. and requiring the cutting out of the slugs from the flat side where the notches H are provided, to permit subsequently closing the rings by compression to substantially circular form. The bracket 34 has an arcuate portion 36 reaching under the cutters 2| in the manner shown in Fig. 1, and there is a shoulder 31 on the end of this arcuate portion at the inner end of the groove 33 to serve as an abutment for the end of the rod 3|, so that the rod will remain stationary as the ram l9 moves forwardly to move the stock 20 at a feed rate toward the cutters 2|, th ram in such movement telescoping on the rod. When the ram has moved to the point where it strikes a lever 38 that is suitably connected with a hydraulic control valve, the ram stops automatically as a result of the automatic operation of the valve, whereupon the operator can, by manual feed rate toward the cutters 2|, the operator makes ready the next stack of ring blanks, as indicatedat 20' in Fig. 1, placing a group of these blanks over a bracket 39 that projects from a housing 40 that is preferably on the same end of the base H with the cylinderl8. A rod 3|, like the rod 3|, rests in a groove 4| in the bracket 39 and has a detachable driving connection at its inner end with a spindle 42 that projects from the housing 40 and has suitable drive means connected therewith in said housing to turn the same fairly slowly but continuously. In that way, the ring blanks are supported on therod 3| and turned individually until the rod 3| rides into the notches after which the rod turns with respect to the ring blanks. Usually all of the rings in a group will have their notches brought into alignment in this way, but should one or more ring in a group fail to be turned to the point of bringing their notches into alignment with the others, the operator will immediately detect that because of the small notches 43 that are provided on the outer peripheries adjacent the notches H (see Fig. 3), and of course these few rings can be turned quickly to the necessary extent to make the stack ready for transfer into the machine onto the V-bed 25, the rod 3| or 3|, as the case may be, bein detached from the spindle 42 and taken hold of at both ends to act as a carrier for the stack of rings in the transfer.

The other rod previously used as a guide for the 11) feeding of ring blanks to the cutters 2|.

stack of rings is then connected with the spindle 42 and used to make read the next stack.

A pair of V-shaped wire springs 44 are mounted on brackets 45 fastened to the back of the sizing ring 22. and are disposed in parallel spaced relation on opposite sides of the bracket 34 and are normally flexed upwardly, as indicated in dotted lines in Fig. 1, by contact on the relatively smooth cylindrical exterior of the stack 20 during the However, when the ram |9 reaches the forward end of its stroke and is then backed away. these springs have an opportunity to spring downwardly behind the last ring blank, as indicated in full lines in-Fig. 1. so as to hold the stack intact and avoid the likelihood of the last one or two, or even three, ring blanks falling out of place and requiring separate handling by the operator. Both sides of the V on each of these springs 44 :1) are at approximately 45 with respect to a vertical, so that these springs will ride into and out of operative position easily; that is to say, when the ram I3 backs away, these springs ride over the back of the endmost ring blank in the stack,

:3 and serve by their light pressure on said blank to prevent toppling over of the last few blanks away from the stack But when the new stack of rings is moved into position behind the other blanks, the springs 44 yield readily and are moved :11; out of the way by pinching contact between the ring blanks as the stacks are moved together.

After the slugs |2 are cut from the ring blanks ID by the cutters 2|, the split rings are guided by their gaps, first by contact at 46 with the at- 35 taching end portion of the bracket 34, and then by contact with a guide blade 41 that extends 'longitudinally of the tapered portion 2'! of the bore of the sizing ring 22. The rings cannot, therefore, turn out of position in their movement 4:) at the feed rate from the cutters 2| to the mill- -ing cutter 23, and of course as soon as the milling cutter 23 starts cutting in the gap of a ring as it passes through the end portion 30 of the bore in the sizing ring, there is no longer any need for any guiding action, as the cut itself forms a guide. The milling cutter 23 projects into the upper end portion 30 of the bore of the sizing ring immediately behind the guide blade 41, as clearly shown in Fig. l, and there is an arcuate notch 48 cut in the sizing ring above the end portion 30 of the bore for clearance of the cutter. A discharge guide chute 43 of I-beam cross-section projects into the end portion 3|! of the bore of the sizing ring below the milling cutter 23, and as the freshly milled rings emerge from the bore they drop onto the chute 49 and are guided between the flanges 50 thereof, the web portion 5| entering the gaps.

A shaft 52 is shown connected to the cutters 2| and, it is understood, is suitably connected to the driving means. The same is true regarding the shaft 53, shown connected to the milling cutter 23. A bracket 54 is shown projecting from the sizing ring 22 over the cutters 21 and carries a downwardly projecting blade 55 which reaches between the cutters 2| and serves as a deflector for the slugs I2 cut from the ring blanks, to avoid likelihood of these slugs being thrown upwardly and outwardly from the machine in the speedy rotation of the cutters, which might cause injury to the operator or a passer-by.

The operation of the machine is believed to be clear from the foregoing description. The splitting and trimming of rings is done quickly and accurately and in such a practical and efllcient manner that the cost of production of piston rings is greatly reduced.

The appended claims have been drawn with a view to covering all legitimate modifications and adaptations.

I claim:

1. In the manufacture of split piston rings, or

the like, a support slidably supporting as a tube a plurality of closed piston ring blanks in stacked relation face to face, whereby each blank is held properly positioned normal to an axis of operation by tight contact of its opposed faces with neighboring blanks in the stack, means for moving the stack axially at a feed rate relative to said support, cutter means intermediate the ends of said support for cutting gaps in said closed blanks in the movement of the stack, said outter means comprising a pair of spaced substantially parallel rotary cut ers, and a deflector between said cutters and arranged to be struck by the slugs cut from the ring blanks and carrei with the cutters in the turning thereoflto stop said slugs and deflect the same in a predetermined direction away from the cutters.

2. In the manufacture of split piston rings, or the like, a support slidably supporting as a tube a plurality of closed piston ring blanks-in stacked relation face to face, whereby each blank is held properly positioned normal to an axis of operation by tight contact of its opposed faces with neighboring blanks in the stack, means for moving the stack axially at a feed rate relative to said support, cutter means intermediate the ends of said support for cutting gaps in said closed blanks in the movement of the stack, said support being substantially horizontally disposed and the stack of ring blanks being movable over the same, and means above said support yieldably en gaging the ring blanks from above to prevent toppling of the rearmost blanks when the feed means is retracted relative thereto as when additional ring blanks to be fed by the feed means are to be placed in the machine.

3. In the manufacture of split piston rings, or the like, a support slidably supporting as a tube a plurality of closed piston ring blanks in stacked relation face to face, whereby each blank is held properly positioned normal to an axis of operation by tight contact of its opposed faces with neighboring blanks in the stack, the closed ring blanks each having a locating notch provided therein on its inner periphery, guide means in spaced relation to one end portion of the support entered in the locating notches to maintain alignment thereof in the movement of the stack, means for moving the stack axially at a feed rate relative to said support, cutter means intermediate the ends of said sup ort in a ignment with the aforesaid guide means for cutting gaps in said closed blanks at the notched portions in the movement of the stack, said cutter means comprising a pair of spaced substantially par-" allel rotary cutters, and a deflector between said cutters and arranged to be struck by the slugs cut from the ring blanks and carried with the cutters in the turning thereof to stop said slugs and deflect the same in a predetermined direction away from the cutters.

4. In the manufacture of split piston rings, or

the like, a substantially horizontal support slidably supporting as a tube a plurality of closed piston ring blanks and a plurality of s"lt piston ring blanks in stacked relation face to face, whereby each blank is held properly positioned normal to an axis of operation by tight contact of its opposed faces with neighboring blanks in the stack, the closed ring blanks each having a locating notch provided therein on its inner periphery, an elongated rod entered in the locating notches to maintain the same in alignment in the movement of the stack, means for demountably supporting oneend of said rod in parallel relation to and above one end portion of said support, a guide for split piston rings over the other end of said support demountably supporting the other end of said rod thereon, means for moving the stack axially at a feed rate relative to said first support, and cutter means intermediate the ends of said support and disposed adjacent the last mentioned end of said rod for cutting gaps in said closed blanks at the notched portions in the axial movement of the stack.

5. In the manufacture of split piston rings or the like, a support slidably supporting as a tube a plurality of closed piston ring blanks in stacked relation face to face, whereby all of said blanks are held positioned normal to an axis of operation by tight contact of their opposed faces with neighboring blanks in the stack, means for moving the stack axially at a feed rate relative to said support, cutter means intermediate the ends of said support for cutting gaps in the closed blanks in the forward feed movement of the stack, guide means extending lengthwise relative to said support in close posterior relation to said cutter means and aligned therewith so as to enter the ring gaps made by said cutter means and prevent rotation of the rings and maintain the gaps in alignment during the further forward feed movement of the stack, a sizing ring at the outer end of said support having an inwardly flared entrance end arranged to receive split rings in the forward feed movement of the stack, the split rings being compressed radially in said sizing ring in the forward feed movement, whereby the gaps cut by the aforesaid cutter means are substantially reduced in Width, and a cutter at the outlet end of said sizing ring in alignment with and closely adjacent the outer entl of said guide means so as to be operable in the gaps and of a thickness slightly greater than the widthof the reduced ring gap to mill the gaps in the rings all to a predetermined width before the rings are discharged from the sizing ring.

6. In the manufacture of split piston rings, or the like, a support slidably supporting as a tube a plurality of closed piston ring blanks in stacked relation face to face, whereby all of said blanks are held positioned normal to an axis of operation by tight contact of their opposed faces with neighboring blanks in the stack, the closed ring blanks each having a locating notch provided therein on its inner periphery, means for moving the stack axially at a feed rate relative to said support, cutter means intermediate the ends of said support for cutting gaps in said closed blanks at the notched portions in the forward feed vmovement of the stack, guide means extending lengthwise relative to said support including one portion in close anterior relation to and aligned with the cutter means slidably received in the locating notches in the closed ring blanks, so as to prevent rotation of said blanks and maintain the notches in alignment with said cutter means during the forward feed movement of the stack relative to said support, said guide means including another portion in close posterior relation to-and aligned with the cutter means so as to enter the ring gaps made by said cutter means and prevent rotation of the rings and maintain the gaps in alignment' during the further forward feed movement 01 the stack,

a sizing ring at the outer end 01 said support 5 having an inwardly flared entrance end arranged to receive split rings in the forward i'eed movement oi the stack, the split rings being compressed radially in said sizing ring in the forward ieed movement, whereby the gaps cut by the aforesaid cutter means are substantially reduced in width, and a cutter at the outlet end oi said sizing ring in alignment with and closely adjacent the outer end 01 said guide means so as to be operable in the gaps and of a thickness slightly greater than the width of the reduced ring gap to mill the gaps in the rings all to a predetermined width before the rings are discharged from the sizing ring.

ALBERT H. BATES.

REFERENCES CITED The following references are of record in the file of this patent:

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